# frozen_string_literal: true module Psych ### # YAML event parser class. This class parses a YAML document and calls # events on the handler that is passed to the constructor. The events can # be used for things such as constructing a YAML AST or deserializing YAML # documents. It can even be fed back to Psych::Emitter to emit the same # document that was parsed. # # See Psych::Handler for documentation on the events that Psych::Parser emits. # # Here is an example that prints out ever scalar found in a YAML document: # # # Handler for detecting scalar values # class ScalarHandler < Psych::Handler # def scalar value, anchor, tag, plain, quoted, style # puts value # end # end # # parser = Psych::Parser.new(ScalarHandler.new) # parser.parse(yaml_document) # # Here is an example that feeds the parser back in to Psych::Emitter. The # YAML document is read from STDIN and written back out to STDERR: # # parser = Psych::Parser.new(Psych::Emitter.new($stderr)) # parser.parse($stdin) # # Psych uses Psych::Parser in combination with Psych::TreeBuilder to # construct an AST of the parsed YAML document. class Parser class Mark < Struct.new(:index, :line, :column) end # The handler on which events will be called attr_accessor :handler # Set the encoding for this parser to +encoding+ attr_writer :external_encoding ### # Creates a new Psych::Parser instance with +handler+. YAML events will # be called on +handler+. See Psych::Parser for more details. def initialize handler = Handler.new @handler = handler @external_encoding = ANY end end end